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Are Your Trees Ready for Summer

Summer is a time where trees, especially young and thin-barked trees, are damaged by weather directly and indirectly. However there are proven methods to reducing or eliminating this damage. First let's talk about what happens to trees during the summer. Then I'll offer some general preventive solutions. 

Sun Scald

Young trees, newly planted trees, and thin-barked trees are most susceptible to a process called sun scald or southwest injury. On a typical summer day, the bark temperature of your tree can increase 20 degrees higher than the air temperature. This can cause tree cells to become so hot that they actually are killed. When the sun is blocked, shadows cause the bark temperature to drop rapidly or a warm day gives way to near freezing temperatures at night. This temperature drop kills these active cells and conducive tissue before it can return to the protection of dormancy.

Once sun scald occurs, cracked areas at the bark level or beneath begin to form which dries out the tree causing leaves or pine needles to appear brown or discolored and bark to die and fall off.

Trees that have been pruned to raise the lower branches, or moved from a shady to a sunny location are also sensitive.  This condition can kill a tree or make it vulnerable to toppling by having the canopy becoming too heavy .

Sun scald can be prevented by wrapping the trunk with a commercial tree wrap. Light-colored wraps work best as darker colors may absorb too much heat. The wrap will reflect the sun and keep the bark at a more constant temperature.

Wrap the trunk from the ground up in an overlapping swirling fashion up to the first branch.  That said, don't remove it too early; wait until after August.

Newly planted trees should be wrapped for at least two summers and thin-barked species up to five years or more until they are established. To repair sun scald damage, cut the dead bark back to live layers.

In high traffic areas


Remember, all trees need watering at least once a month throughout the winter. Following this advice will give your trees a greater chance of making it through the winter unscathed.

Jomar Tree Service • P.O. Box 4803 • Cave Creek, AZ • 85327 – serving the Phoenix metro area – 602-285-0285